如何在SQL Server数据库中列出用户定义的类型？

I need to enumerate all the user defined types created in a SQL Server database with CREATE TYPE, and/or find out whether they have already been defined.

我需要使用CREATE TYPE枚举在SQL Server数据库中创建的所有用户定义类型，和/或找出它们是否已经定义。

With tables or stored procedures I'd do something like this:

使用表或存储过程，我会做这样的事情：

if exists (select * from dbo.sysobjects where name='foobar' and xtype='U')
    drop table foobar

However I can't find the equivalent (or a suitable alternative) for user defined types! I definitely can't see them anywhere in sysobjects.

但是我找不到用户定义类型的等价物（或合适的替代品）！我绝对无法在sysobjects中看到它们。

Can anyone enlighten me?

任何人都可以开导我吗？

3 个解决方案

#1

Types and UDTs don't appear in sys.objects. You should be able to get what you're looking for with the following:

类型和UDT不会出现在sys.objects中。您应该能够通过以下方式获得所需内容：

select * from sys.types
where is_user_defined = 1

#2

Although the post is old, I found it useful to use a query similar to this. You may not find some of the formatting useful, but I wanted the fully qualified type name and I wanted to see the columns listed in order. You can just remove all of the SUBSTRING stuff to just get the column name by itself.

虽然帖子很旧，但我发现使用类似的查询很有用。您可能找不到一些有用的格式，但我想要完全限定的类型名称，我希望看到按顺序列出的列。您可以删除所有SUBSTRING内容以仅获取列名称。

SELECT USER_NAME(TYPE.schema_id) + '.' + TYPE.name      AS "Type Name",
       COL.column_id,
       SUBSTRING(CAST(COL.column_id + 100 AS char(3)), 2, 2)  + ': ' + COL.name   AS "Column",
       ST.name                                          AS "Data Type",
       CASE COL.Is_Nullable
       WHEN 1 THEN ''
       ELSE        'NOT NULL' 
       END                                              AS "Nullable",
       COL.max_length                                   AS "Length",
       COL.[precision]                                  AS "Precision",
       COL.scale                                        AS "Scale",
       ST.collation                                     AS "Collation"
FROM sys.table_types TYPE
JOIN sys.columns     COL
    ON TYPE.type_table_object_id = COL.object_id
JOIN sys.systypes AS ST  
    ON ST.xtype = COL.system_type_id
where TYPE.is_user_defined = 1
ORDER BY "Type Name",
         COL.column_id

#3

To expand on jwolly2's answer, here's how you get a list of definitions including the standard data type:

为了扩展jwolly2的答案，以下是如何获得包括标准数据类型在内的定义列表：

-- User Defined Type definitions TP 20180124
select t1.name, t2.name, t1.precision, t1.scale, t1.max_length as bytes, t1.is_nullable
from sys.types t1
join sys.types t2 on t2.system_type_id = t1.system_type_id and t2.is_user_defined = 0
where t1.is_user_defined = 1 and t2.name <> 'sysname'
order by t1.name

#1